Final answer:
George Washington contributed to the founding of the United States by leading the Continental Army, becoming the first President, and playing a key role in drafting the Constitution.
Step-by-step explanation:
George Washington made several important contributions to the founding of the United States. Firstly, he led the Continental Army during the American Revolution, which ultimately resulted in victory and independence from Great Britain. Secondly, Washington became the first President of the United States, serving two terms and establishing many important precedents for the office. Lastly, Washington played a crucial role in the drafting of the Constitution as the President of the Philadelphia Constitutional Convention in 1787.